Referring to FIG. 1, a conventional light emitting diode (LED) module 1 is configured to receive a power source signal Vcc, and includes a plurality of LED packages 11 and a plurality of limiting resistors 110 corresponding respectively to the LED packages 11. Each of the LED packages 11 includes a first LED 111, which is connected in series with the respective one of the limiting resistors 110, a second LED 112 and a third LED 113. In each of the LED packages 11, the first, second and third LEDs 111, 112 and 113 respectively have anodes that are electrically connected with each other for receiving the power source signal Vcc, and are activated by the power source signal Vcc to emit red light, green light and blue light, respectively.
For each of the LED packages 11, since the first LED 111 is made of a material different from that of the second and third LEDs 112 and 113, which are made of a same material, a forward voltage of the first LED 111 during light emission (around 2 volts) would be different from a forward voltage of each of the second and third LEDs 112 and 113 (around 3 volts). Therefore, in order to mitigate the issue of electric leakage in the first LEDs 111 or the issue that the first LEDs 111 may burn out due to an excessive driving voltage during light emission, for each of the LED packages 11 in the conventional LED module 1, the limiting resistor 110 is necessary for reducing the voltage across the first LED 111.
However, the inclusion of the limiting resistors 110 may cause relatively high energy consumption which will lead to heat accumulation in the conventional LED module 1. As a result, the materials of the first, second third LEDs 111, 112 and 113 may deteriorate in the long term, and efficiency of light emission for each of the LED packages 11 may thus diminish. To make matters worse, the LED packages 11 may even fail to function. The incorporation of the limiting resistors 110 also induces more complicated circuit architecture and higher manufacturing cost.